PAT Advanced 1154 Vertex Coloring (25 分)

Posted 2022-12-12 littlepage

A proper vertex coloring is a labeling of the graph‘s vertices with colors such that no two vertices sharing the same edge have the same color. A coloring using at most k colors is called a (proper) k-coloring.

Now you are supposed to tell if a given coloring is a proper k-coloring.

Input Specification:

Each input file contains one test case. For each case, the first line gives two positive integers N and M (both no more than 1), being the total numbers of vertices and edges, respectively. Then M lines follow, each describes an edge by giving the indices (from 0 to N−1) of the two ends of the edge.

After the graph, a positive integer K (≤ 100) is given, which is the number of colorings you are supposed to check. Then K lines follow, each contains N colors which are represented by non-negative integers in the range of int. The i-th color is the color of the i-th vertex.

Output Specification:

For each coloring, print in a line k-coloring if it is a proper k-coloring for some positive k, or No if not.

Sample Input:

10 11
8 7
6 8
4 5
8 4
8 1
1 2
1 4
9 8
9 1
1 0
2 4
4
0 1 0 1 4 1 0 1 3 0
0 1 0 1 4 1 0 1 0 0
8 1 0 1 4 1 0 5 3 0
1 2 3 4 5 6 7 8 8 9

Sample Output:

4-coloring
No
6-coloring
No

#include <iostream>
#include <unordered_set>
#include <algorithm>
using namespace std;

int main()

    int vertx_num,edge_num,x,y;
    cin>>vertx_num>>edge_num;
    pair<int,int> p[edge_num];
    for(int i=0;i<edge_num;i++)
        cin>>p[i].first>>p[i].second;
    int test;cin>>test;int color[vertx_num];
    while(test--)
        bool no=false;unordered_set<int> s;
        for(int i=0;i<vertx_num;i++)
            cin>>color[i];
            s.insert(color[i]);
        
        for(int i=0;i<edge_num;i++)
            if(color[p[i].first]==color[p[i].second])
                cout<<"No"<<endl;
                no=true;
                break;
            
        
        if(!no) cout<<s.size()<<"-coloring"<<endl;
    
    system("pause");
    return 0;